Are social networking platforms a red flag for investors? If so, why?

I recently have been having conversations with a lot of founders and investors, and one thing I've noticed is that most investors are fully against the idea of investing in a networking platform of any sorts.

There have been social media platforms for literally every group of people, and somehow the one group of people who are sidelined or rather forced to fit in, are students. I experienced this first hand when I wanted to connect with a developer from my university and my only options were LinkedIn and Instagram, and considering LinkedIn profiles are created by students only when they're about to graduate to find jobs, and every working professional wanted to be financially incentivised (rightfully so), it was extremely difficult for me (a second year student then) to find the right guy.

That's when I realised even though there are millions of students, there is no single platform that helps them connect with each other in any way. That's when I started building Chalk, with a vision to build a global student ecosystem, aiming to help students connect and collaborate with each other based on skillsets.

There's more, the community - discussion forum and some sort of a project showcase are just parts of the product, as I couldn't rely only on ads to make revenue and be a promising revenue model. Which is why I added an Events and a Mentorship section. Events would list various student events happening inside and outside a university, and Mentorship is pretty straightforward. Basically, aiming to build the go-to student platform.

But after all this, one thing I still hear is social networking platforms are red flags for an investor. Is it really impossible to build a new social networking platform? If not, then what am i doing wrong?